The present invention relates to a method of determining parentage in bison and domestic cattle using distinct microsatellite loci.
Bison once numbered in the millions in North America but due to the population bottleneck experienced in the late 1800's, bison numbers were reduced to no more than 300 individuals by 1880 (Coder 1975; Dary 1989). Almost all of the bison alive today can be traced back to five populations that were used to repopulate most of the extant public and private herds (Coder 1975). Current semi-wild bison populations are fragmented among public parks and sanctuaries throughout the United States and Canada. However, the vast majority of bison today reside on private ranches where they are raised for meat production. Recently, Mommens et al. (1998) demonstrated that bovine microsatellites are better suited for parentage testing in bison than conventional blood typing due to a greater degree of variation. However, their sample was limited to a single herd located in Belgium, which probably does not represent the actual genetic variation found in bison in North America.
Currently, parentage testing in domestic animals is based on exclusionary techniques using genetic markers. An offspring is tested assuming one known parent and one or a limited number of candidate parents. If only one candidate parent is left non-excluded, that parent is assigned parentage to the offspring. Although one non-excluded parent may be the true parent, there exists the possibility that other non-excluded candidate parents exist in the population but were not considered. A likelihood based testing procedure is more appropriate for situations in which there are many candidate parents and obtaining a known parent is difficult. Using likelihood based procedures, all potential parents are considered as candidates and there is no need to identify a known parent prior to testing.